DCNA

Kralendijk – The Dutch Caribbean Nature Alliance’s (DCNA) bi-annual board meeting took place during the recent convention held in Curaçao. Their Excellencies, Governors Holiday and Boekhoudt from Sint Maarten and Aruba, as well as Mr. Jaime Saleh, patron of DCNA, were present as observers for crucial discussions on governance and DCNA’s strategic vision moving forward.

The arrival of Their Excellencies, Governors Holiday and Boekhoudt

Strategic vision

After 15 years of existence, DCNA has the requisite tools needed to enable its member organizations to withstand looming challenges. While the immediate support to parks due to COVID-19 remains essential, DCNA must also focus on the impact of climate change, which is an existential threat to the lives and livelihoods of Dutch Caribbean Communities.

Director of DCNA, Tadzio Bervoets, says “it is crucial to increase the resiliency of our Protected Area Management Organizations to hold out against the myriad external shocks that are heading our way due to global warming. Another important strategic objective is to advice our local governments more effectively since they remain an important stakeholder.”

Good governance

In order to better serve the Protected Area Management Organizations, DCNA will move from a one-tiered to a two-tiered governance structure. This will allow management to focus on routine managerial tasks, while the board handles long-term decision-making and strategic planning. During the board meeting, the team dealt with the basic good governance procedures, such as approval of the budget for 2022 and approval of the 2021 Financial Statements. The board meeting also offered an opportunity for the secretariat and the Protected Area Management Organizations to share activities carried out since the last board meeting in April.

The way forward

The board agreed on a strategic plan for the period of 2021-2030 that takes into consideration the common challenges among the nature conservation organizations as well as island-specific needs. Raising awareness of these developments is an import aspect of DCNA’s goals. “We are in the final stages of hiring a PR and Information Officer who will increase our own capacity to communicate and help the parks to communicate with their respective communities as well”, says Bervoets.

More information about the DCNA board meeting can be found on DCNA’s Facebook page: DutchCaribbeanNatureAlliance

Article published in the Special Edition BioNews:  2021 DCNA Convention

Willemstad – A group of engaged teens and young adults had the opportunity to discuss youth engagement in nature conservation and nature education during the Youth and Nature Education Symposium organized by the DCNA as part of their annual convention.

Youth Participation

One of the priorities for DCNA and its member organizations is to engage the youth in their work of safeguarding nature in the Dutch Caribbean. After a successful Junior Rangers Exchange held during the DCNA convention of 2019, the expectations for this year’s symposium were high. DCNA chairlady, Mrs. Hellen van der Wal firmly believes that “the younger generation has a future today. They have a voice, and we should listen more to them”. The youth symposium that recently took place during the DCNA convention focused on nature education and the 2030 Agenda. A total of seventeen participants between the ages of fifteen and twenty-three had the opportunity to strategize and discuss how they would like to see nature conservation develop on their islands, how they would like to see their governments committing more to nature conservation, and how they see their lives and livelihoods impacted by climate change.

Princess Beatrix together with the participants of Young Ones United To Heighten Curaçao (YOUTH-C)

Thorough Preparation

Before discussing the topics at hand and preparing the conclusions, the participants went through a preparation stage that lasted three months. They learned more about the environment in general, the Sustainable Development Goals and further developed their debating skills. The specific topics that they prepared to discuss were the environment in general, life under water, climate change, and nature education.

Symposium Program

The participants were welcomed by Sietske van der Wal, representing Aruba National Parks Foundation. The keynote speech that followed was delivered by Dahlia Hassell-Knijff, projects officer at DCNA who started her career in nature conservation as a Saba youth ranger since the age of seven. After a keynote conversation led by Mr. Elton Villareal, the youth participants got the opportunity to present their conclusions to Her Royal Highness Princess Beatrix of the Netherlands, patron of the DCNA.

The Way Forward

There was marked interests amongst the audience for the various perspectives brought forward by the participants. They came up with three propositions: an awareness campaign, a movement to clean up the island on a weekly basis (‘Cleaning Sundays’), and a youth council for matters regarding the environment.

Mr. Tadzio Bervoets, director of the DCNA, wrapped up the afternoon concluding that “the future of nature conservation looks exceedingly bright”.

“The youth is generally very eager to learn and after witnessing today’s discussions and presentation, we are particularly driven to prepare an inspiring and educational program for them next year.”, says Achsah Mitchell from St. Eustatius National Parks.

The next official engagement with the youth will take place in March 2022 in St. Eustatius.

More information about the Youth Symposium can be found on DCNA’s Facebook page: DutchCaribbeanNatureAlliance

Article published in Special Edition BioNews: 2021 DCNA Convention

Willemstad – The 2021 Dutch Caribbean Nature Alliance (DCNA) Convention began with a workshop on climate change resiliency. The workshop served as a platform for knowledge sharing between researchers from the Royal Netherlands Institute for Southeast Asian and Caribbean Studies (KITLV), and Dutch Caribbean experts. The participants discussed the impact of climate change on marine ecosystems in the Dutch Caribbean and related issues.

Different perspectives

This workshop is part of a pilot project that aims to unpack the impact of climate change on marine protected areas in Indonesia and the Caribbean. To get an accurate understanding of the key issues and challenges, listening to experts from various fields within and outside academia is key. Yvonne Kunz, main postdoctoral researcher at KITLV notes that “if we want to understand the impact of climate change on marine protected areas, we must engage with those who experience this impact firsthand. This is our main motivation to obtain information from as many sources as possible.”

Climate change resiliency workshop

Collaboration with DCNA

David Kloos, project lead at KITLV, further explains that “DCNA has been involved from the very beginning of this pilot project. They represent a key stakeholder in the Caribbean.” The project is a comparative analysis, and the stakeholders are taking care to ensure that crucial comparisons are made from various angles. Mr. Kloos says that “policy versus actual operations is one aspect, but also the number of years of existence of the marine protected areas. We have chosen to investigate protected areas in Aruba and Bonaire, where there is a difference in years of existence. By comparing Indonesia and the Caribbean, KITLV can analyze yet another aspect. Whereas in the Caribbean the need to protect marine areas takes on a ‘bottom-up’ approach, in Indonesia the initiatives are more government-led. In addition, these contrasts facilitate the comparison and analysis of different conservation narratives.”

Climate change impact

For some, climate change is seen as a theoretical issue, even though the Caribbean region has already started to experience its effects.

Melanie Meijer zu Schlochtern of DCNA states that “we have observed a deterioration of our coral reefs. The majority of our population may not be aware of this, but if we do not stop this decline, we can end up with green water, instead of the crystalline blue seas that we know today. If we can only become more aware of the economic value of these coral reefs, we will soon start to realize that further decline will have a direct negative impact on tourism, one of the main economic pillars of our islands.”

Everyone can and must contribute to mitigation of the impact of climate change.

This pilot project is being conducted in partnership with the Netherlands Institute for Ecology (NIOO), the Netherlands Institute for Advanced Studies (NIAS), and various partners in Indonesia and the Caribbean. More information about this pilot project and practical tips can be found on DCNA’s Facebook page: DutchCaribbeanNatureAlliance.

Article published in the Special Edition Bionews: 2021 DCNA Convention and BioNews 50

Kralendijk – The upcoming convention of the Dutch Caribbean Nature Alliance (DCNA) will focus on governance, climate change, and youth engagement in nature conservation. All six Protected Area Management Organizations of the Dutch Caribbean are joining forces to strengthen strategic nature management policies for the coming years. The Patron of the Dutch Caribbean Nature Alliance, Her Royal Highness Princess Beatrix of the Netherlands, will also attend the Convention, which will take place in Curaçao from Tuesday, November 23 to Friday, November 27.

Princess Beatrix meets Tadzio Bervoets, the Director of DCNA, in Saba. Photo credit: Lincoln Charles

Governance in times of recovery

The significant disruptions caused by the pandemic have reminded us that our ecosystems are critical to our success as small island developing states. Further development in these challenging times should be sustainable, with the aim to conserve the biodiversity of the islands, which supports the unique tourism product of the Dutch Caribbean.

One of the highlights of convention will be the board meeting, which will be held in-person for the first time after almost two years of virtual engagements. Tadzio Bervoets, Director of the Dutch Caribbean Nature Alliance said that “even though we are convinced that we can achieve more by joining forces, we realize that governance is equally important, which is why our board meeting will address our governance structure and our strategic vision for the time to come.”

Climate change

The Dutch Caribbean islands are now emerging from the effects of the pandemic. However, the Caribbean region is also experiencing another crisis that will have significant negative impact on the ecosystems that are critical to the sustainable economies that the islands need to build. One of the workshops at the Convention will focus on climate change resiliency. This topic could not be timelier, considering the renewed commitment of global leaders to keep the global average temperature increase below 2° Celsius. DCNA’s chairlady, Hellen van der Wall noted that “we in the Caribbean are at the frontlines of the climate change crises and it is only through using the goods and services our nature provides us that we can become resilient as Dutch Caribbean societies.” The workshop will highlight a pilot project that seeks to analyze and understand the impact of climate change on marine protected areas in Indonesia and the Caribbean. The long-term goal of the pilot is to set up a larger research program that will help to develop responses to the dynamic consequences of climate change.

Youth engagement

Sustainability is about meeting current needs without compromising the ability of future generations to meet theirs. With this understanding, the youth are considered crucial stakeholders in DCNA’s work. Since 2019, DCNA Conventions have included a youth symposium that provides platforms for youth to share their views. Their inputs have proven valuable over the years and have led to the creation of youth nature programs. This year’s symposium will also feature key conversations focused on the importance of investing in nature education in order to create ownership of natural areas. Even though the next generation of young environmental stewards seem to be naturally inclined to practice responsible use of the available natural resources, it is imperative to provide them with the necessary tools at a young age.

More information about the DCNA Convention can be found on the DCNA’s Facebook page: DutchCaribbeanNatureAlliance.

Article published in Special Edition BioNews: 2021 DCNA Convention

From big litigation to renovations for their new sea lab, 2022 promises to be a banner year for the Saba Conservation Foundation (SCF).  SCF recently presented at the Dutch Caribbean Nature Alliance (DCNA)  Board Meeting, highlighting exciting new projects on the horizon.

Just over five years ago, a 48 meter super yacht, Elsa, broke loose of her mooring and ran ashore, leading to several thousand liters diesel fuel spilling into the sea.  SCF with assistance from DCNA completed an environmental impact assessment (EIA), showing minor damage to the marine habitat.  A second EIA was commissioned by the insurance company, where they also found no notable evidence to claim compensation for marine damage. Nonetheless, after a lengthy legal battle by the vessel’s owner, John Deuss of Elsa Shipping, against the State, Island Government and SCF , the court eventually decided in favor of the island and refuted all claims by the opponent.  However, Elsa Shipping appealed the ruling and the court case went into second instance and proceedings are still ongoing. Important lessons have been learned from the unfortunate incident and the SCF is now much better prepared to respond to such situations in the future, with the ultimate goal to protect the coastal resources of Saba.

Key Projects

Successes go beyond the courtroom, however, with a number of other key projects meeting important milestones.  SCF executed an important bird monitoring program to track the local populations of tropicbirds.  SCF also attended the Land Bird Monitoring Workshop in the Dominica Republic to help shape future bird projects for the island. In addition, coral mapping at the proposed harbor construction site was completed with a follow-on coral relocation trial.

Much progress has been made with the establishment of an ethno botanical garden at the SCF Trail Shop property in Windwardside. The garden will not only act as an educational center for the foundation’s after school programs and become a new tourist attraction, displaying indigenous local flora, but also serve as the focal point for the upcoming reforestation project, that will be initiated in mid 2022.

In an effort to further increase local coral reefs, important coral nurseries were established, which included the deployment of 95 artificial reef “Moreef” balls that boost a 95% coral survival rate.  Paired with a successful phase 1 of the Diadema project, which spawned nearly 400 long-spined black urchins in their nursery, the future for coral reef restoration is off to a promising start.  Renovations to build the new Saba Sea Lab at the old power plant have also started, which will help elevate these projects and build capacity on island for future endeavors.

Financial Gaps

Growth is not without limitations, however, as SCF stressed the potential financial shortfalls in the upcoming years.  Although the Nature and Environmental Policy Plan (NEPP) for the BES islands slated exciting new projects to dramatically improve the state of nature, this plan requires proper funding and an increase in capacity to manage and execute these projects.  Assuming a baseline revenue of 2018, SCF estimates a financial gap of nearly US$880,000 per year, thus creative and sustainable solutions are needed immediately.

There is also a need for additional external staff to complete reforestation projects, invasive species monitoring, removal of free roaming grazers, management of beach enhancements, monitoring sea water quality, keystone and flagship species enforcement not to mention capital investments for facilities for waste vessel discharge. Although Saba’s future looks auspicious, without serious and sustainable investments the island will fall short of the visions laid out in the NEPP.

Working Together

The DCNA board meeting is an important opportunity for each of the Protected Area Management Organizations in the Dutch Caribbean- – the Aruba National Parks Foundation (FPNA), STINAPA Bonaire, CARMABI Curaçao , Saba Conservation Foundation (SCF), Nature Foundation St. Maarten (NFSXM), St. Eustatius National Parks (STENAPA) – to collaborate, share resources and exchange information and ideas. Working together, each island can learn from the others, maximizing their successes and learning from the more challenging experiences.

Article published in Special Edition BioNews: 2022 Park Updates

The Caribbean Research and Management of Biodiversity (CARMABI) recently highlighted some big changes and impressive achievements for Curaçao during the last Dutch Caribbean Nature Alliance (DCNA) Board Meeting.  Achievements include the declaration of a new marine park at East Point as well as the opening of two other new nature parks around the corner. Also highlighted was the recovery of vegetation and rebound of biodiversity for Christoffel Park. 2022 promises to be an exciting year for conservation on the island.

Christoffel National Park

The Christoffel National Park, the largest and oldest protected area of Curaçao and the most biodiverse area within the ABC islands, is an inspiring case study of habitat revival for the region. The park is formed around three former plantations and areas of the park that were used for agriculture, the clear-cutting of trees and the roaming of introduced goats and other herbivores. Due to the reduced importance of plantations practices since the 1960’s and the removal of goats in the 1990’s, change in vegetation has been observed and documented between 1985 and 2019. This successful management of the park becomes clear with the strong increase in cover and abundance of different native plants including trees, bromeliads, orchids, palms. The recovering vegetation of the Christoffel National Park is likely directly influencing the abundance of native animals, including the Curaçao White-tailed deer, which will be intensively studied over the next years.

New parks

In other exciting news, the opening day of the new Curacao Rif Mangrove Park is just around the corner.  This park includes a beautiful boardwalk and watch tower, giving unprecedented access to these mangroves.  Future plans for a visitor’s center will really help visitors and locals alike appreciate the wonders of the island’s mangrove forests.

Another new upcoming park is National Park Rif St. Marie- Hermanus, located in a Ramsar area- wetland of international importance- including a historical lime kiln.

Curaçao Marine Park

Recent achievements also extend beneath the water, when in November 2020, the Curacao Marine Park was officially opened by DCNA’s Patron Her Royal Highness Princess Beatrix.  In addition, Curaçao’s Marine Park announced that on March 7th, 2022, they had their first patrol with their new boat, Yaru, which will serve to promote safe and sustainable use within the park for many years to come.

In the National Marine Park, the Proteus Underwater Research Station will be located. This will allow scientists to live and conduct research directly from the ocean floor. PROTEUS™ is a project of the Fabien Cousteau Ocean Learning Center (FCOLC) and is Fabien Cousteau’s vision. 

Research

There have also been a number of critical research studies conducted around the island.  Coral trends, although in general decline, have noted some locally focused rapid regrowth since 2014.  This is a beacon of hope for coral restoration and conservation on the island.  Improved models of the coastline and groundwater will further improve information available to land area managers for future projects.

CARMABI noted that there is still a number of areas in which research is needed. In 2022, they will continue to investigate forest plots in the Christoffel National Park.  CARMABI emphasizes the need to focus on native plants and continuously increases efforts in the in-house native plant nursery to research these species and educate the general public on the importance of native plants.  In addition, as wetlands continue to gain recognition for their importance, both in environmental services as well as building resilience against climate change, CARMABI stressed the importance of further research within local mangrove forests areas.

Working Together

The DCNA board meeting is an important opportunity for each of the Protected Area Management Organizations in the Dutch Caribbean- – the Aruba National Parks Foundation (FPNA), STINAPA Bonaire, CARMABI Curaçao , Saba Conservation Foundation (SCF), Nature Foundation St. Maarten (NFSXM), St. Eustatius National Parks (STENAPA) – to collaborate, share resources and exchange information and ideas. Working together, each island can learn from the others, maximizing their successes and learning from the more challenging experiences.

CARMABI – Curaçao Marine Park Team. Left to right standing: Joël Dominguez (ranger), Paul Stokkermans (CARMABI Directeur), Kevin Philbert (ranger). Left to right squatted: Roland de Cuba (ranger), Duvan Rios Ospina (Head Department Mariene Parken)

Article included in Special Edition: 2022 Park Updates

Receives Letter of Support from Royal Patron Princess Beatrix of the Netherlands

The Nature Conservation Network Organization the Dutch Caribbean Nature Alliance (DCNA) will host its next Board Meeting on Sint Maarten from the 14th to the 17th of March. DCNA Board meetings are critical for discussing and strategizing on the most effective way to support protected area management organizations in the Dutch Caribbean, especially in light of the significant challenges brought about by the global Covid-19 pandemic and other pressures faced by the Park Management Organizations. Park Management Organizations also have the opportunity to update attendees  on some of the challenges and successes the parks are experiencing as they continue to safeguard nature in the Dutch Caribbean. Various governance decisions are also taken during the biannual meetings, including decisions related to financial good-governance, the disbursement of the DCNA Conservation Trust Fund and the support the DCNA network provides in terms of its regional and international lobby on behalf of the conservation organizations in the Dutch Caribbean.

The DCNA conservation network provides support to the Protected Area Management Organizations of all six islands of the Dutch Caribbean: Aruba National Parks Foundation, STINAPA Bonaire, CARMABI Curaçao, STENAPA St. Eustatius, the Saba Conservation Foundation and the Sint Maarten Nature Foundation. Another critical component discussed during the Board Meeting is the importance of implementing a strategy which will help foster the development of sustainable tourism for the islands, enabling the Dutch Caribbean to emerge from the challenges brought about by the Pandemic with a greater focus on green and blue economies. Aside from conservation managers and the various experts of the Board of DCNA, observers from the International Union for the Conservation of Nature (IUCN-NL), World Wide Fund for Nature (WWF–NL), BirdLife Netherlands, Observation International and the Ministry of Agriculture, Nature and Food Quality (LNV) also participate in DCNA Board Meetings.

DCNA’s Royal Patron Her Royal Highness Princess Beatrix of the Netherlands also recently commended the Conservation Network Organization for their recently organized Board Congress held last November in Curacao. During an official letter from the Royal Palace to the Chair of DCNA Dr. Hellen van der Wal, the Princess commended the organization on their continued support for the protected area management organizations on all six islands while especially providing the means to the nature organizations to execute their tasks.

DCNA Secretariat’s Office Manager Emeray Martha-Neuman presents a gift to Her Royal Highness Princess Beatrix for being the Royal Patron of DCNA

Article included in Special Edition: 2022 Park Updates

Between November 23rd and the 27th, the Dutch Caribbean Nature Alliance (DCNA) held its annual Nature Convention on Curaçao.  Due to covid-19 restrictions, the last conference had to be held virtually, so all participants were eager to meet face to face again.

Throughout the week, the Dutch Caribbean park authorities met to discuss critical issues affecting their parks.  The conference focused on three main topics:

• Governance in Times of Recovery
• Increasing Resilience to Climate change
• Improving Youth engagement

This conference was the perfect opportunity for all six Protected Area Management Organizations of the Dutch Caribbean to discuss how to strengthen strategic nature management policies for the coming years. In addition, the Patron of the Dutch Caribbean Nature Alliance, Her Royal Highness Princess Beatrix of the Netherlands was also in attendance.

CONVENTION WORKSHOPS

During the convention there were three workshops held on the following projects.  Learn more below:

Automatic Species Recognition Tools

With this project, the Dutch Caribbean Nature Alliance (DCNA), Naturalis Biodiversity Center and Observation International will work together to create image recognition for the animals and plants found on the six islands of the Dutch Caribbean. This image recognition model will be aimed at the marine and terrestrial species of the Dutch Caribbean and will be made available via the internet and an app for all observers. In addition, the observations will be reviewed by an active validator team for quality control. These activities will lead to more observers, more sightings and a higher quality of data in the Caribbean part of the Kingdom of the Netherlands.

During the DCNA convention, a workshop was held to set-up and train a local validator team. Click here for more information >

Climate change and governance in Indonesia and the Caribbean: A pilot program on marine protected areas (MPA’s) and coastal nature reserves

KITLV, NIOO, NIAS, and WUR joined forces in a KNAW-funded interdisciplinary study of the impact of climate change on social-ecological systems (SES). A consortium including Indonesian and Caribbean partners in academia and NGOs will co-create and implement pilot research in four coastal zones in these two tropical archipelagoes. Concretely, it seeks to write a joint ecological and sociopolitical history of selected protected areas in both regions and its effects in the present.

Click here for more information >

DCNA 2030- Strategy sessions

During the convention, the DCNA held two halfway strategy sessions with the board to align around a shared vision and core competencies, sharpen understanding of the trend and future challenges and build commitment towards the organization’s direction to achieve their collective aspiration.

• The Dutch Caribbean Nature Alliance will discuss three critical topics at the upcoming DCNA Convention
• Dutch Caribbean Nature Alliance facilitates platform for investigation of marine protected areas in the Caribbean
• Dutch Caribbean Nature Alliance Provides Platform for Youth Engagement in Nature Conservation During Symposium Held in Curaçao
• Dutch Caribbean Nature Alliance is Preparing Dutch Caribbean Conservation Organizations to Withstand External Shocks
• Dutch Caribbean Nature Alliance Highlights Nature’s Economic Value

      

A student of University of Amsterdam and a staff researcher of Naturalis Biodiversity Center and University of Groningen recently published the first detailed report of hard corals digesting salps in the Caribbean.  Three species of hard corals were spotted digesting salps in Curacao’s Director’s Bay in July 2021, providing exciting new insight into the coral reef predation.   

Salps, also known as sea grapes, are gelatinous, barrel-shaped tunicates. Multiple salp bodies can link together creating whole colonies, able to move through the water column by utilizing one of the most efficient jet population systems found in the animal kingdom.  Previously, fish were thought to be the main predators of salp, however new information is emerging on predation by corals as well.

Sea Grapes

To date, there is limited information on salpivorous corals. As salps are relatively large planktonic animals, it was assumed that predation by corals was limited to those with polyps with mouth’s larger than one centimeter, large enough to engulf an entire salp. However, observations from the Mediterranean have found polyps from smaller mouthed corals working together to digest larger catches, hinting that salp may be an important food source across a wide variety of coral species.

Observations on Curacao

In July 2021, a swarm of these salps were spotted in Curacao’s Director’s Bay.  Upon closer inspection, Lars J. V. ter Horst, student of University of Amsterdam also found captured salps amongst three different species of hard corals: yellow finger coral (Madracis auretenra), maze coral (Meandrina meandrites), and great star coral (Montastraea cavernosa).  He contacted Bert W. Hoeksema at Naturalis and the University of Groningen who previously published about salpivorous corals in Malaysia and Thailand. They then proceeded to publish a report together. This is important as this was the first record of yellow finger coral and maze coral as salp predators.  In addition, since salp swarms are frequent observed within the Caribbean, these findings hint that these swarms could potentially be a more common and widespread food source for corals than previously thought.

A salp caught by multiple polyps of the branched coral Madracis aurentenra (photo Lars J.V. ter Horst)

Implications

These findings provide exciting new insight into coral reef ecology and the importance of salp swarms as a food source. As coral reefs continue to face increasing pressures, a more holistic understanding of their dynamic ecosystems will be crucial for conservation management moving forward.

Find out more information by reading the full report on the Dutch Caribbean Biodiversity Database using the button below.

https://www.dcbd.nl/document/salpivory-colonial-reef-corals-cura%C3%A7ao...

Article published in BioNews 49

New research from Wageningen University, University of Amsterdam and Florida International University highlighted the role herbivorous fish species plays in staving off nonnative seagrass invasions.  A healthy and diverse fish population can provide top-down control by grazing on invasive seagrass species, minimizing its overall invasion.

Invasive species can pose a direct threat to native species through competition and hybridization. Species which evolved to reproduce and spread rapidly generally have a greater chance at survival, and when introduced to a new environment, can out compete slower growing native species. This is certainly the case for Halophila stipulacea, a seagrass native to the Red Sea, Persian Gulf and Indian Ocean which has been rapidly gaining habitat within the Caribbean since its first reported sighting in 2002. This species is quickly outpacing native Thalassia testudinum (turtle grass) and Syringodium filiforme (manatee grass), both of which provide critical habitat, coastal protection and foraging grounds. 

Mixed area of Halophila stipulacea (shorter blades) and Thalassia testudinum (longer blades). Photo Credit: Fee Smulders

The Study

A new study by Wageningen University and Research, the University of Amsterdam and Florida International University worked to improve overall understanding of the controlling factors in the spread of invasive seagrasses.  Researchers investigated the influences of local nutrient enrichment (nitrogen and phosphorus) as well as the impact of large herbivorous fish on the growth and expansion rates of Halophila stipulacea. The study took place between 2018 and 2019 within two seagrass meadows, Lac Bay on Bonaire and Barcadera on Aruba.

Seagrass Meadow. Photo Credit: Fee Smulders

The Results

At both sites, nutrients were added to selected seagrass plots by using slow-release fertilizer. Interestingly, only on Bonaire did these excess nutrients actually result in a reduction of H. stipulacea’s expansion into the turtle grass meadows, while native seagrass was unaffected.  This is believed to be because on Bonaire, herbivore fish abundance is 7 times greater and diversity is 4.5 times higher than on Aruba, therefore excess nutrients likely enticed more fish to graze therefore limiting the spread of the invasive seagrass.  Native seagrass is more adapted to high grazing pressures, during this study grazing pressure increased after nutrient enrichment but only the invasive species showed lower expansion rates.  In fact, the exclusion of large herbivorous fish (like parrotfish) doubled the invasive expansion rates within sandy patches on Bonaire, further strengthening this theory.

Top-Down Approach

This study highlights the importance of holistic approaches to ecosystem management.  Healthy and diverse fish communities can provide top-down control to invasive species expansion Increasing grazing pressures can help reduce the competitive advantage of fast-growing species, slowing down invasion of non-native species. The key to seagrass restoration and conservation could lie in protecting the biodiversity of these fragile areas.

To learn more, please find the full report on the Dutch Caribbean Biodiversity Database using the button below.

https://www.dcbd.nl/document/fish-grazing-enhanced-nutrient-enrichment-m...

Article published in BioNews 49